collaborators

9 papers

cs.CL2026

BALTO: Balanced Token-Level Policy Optimization for Hallucination Mitigation

Ning Li, Zixuan Guo, Yan Xu +7

Hallucinations remain a major obstacle to deploying large language models (LLMs) in knowledge-intensive settings, where generated responses must be faithfully grounded in provided…

cs.LG2026

Breaking the Tokenizer Barrier: On-Policy Distillation across Model Families

Yifan Niu, Han Xiao, Dongyi Liu +4

On-Policy Distillation (OPD) has become a core technique in the post-training of Large Language Models (LLMs) for transferring knowledge from domain experts to student models. Howe…

cs.DC2026

Efficient Scaling of LLM Training with Flexible Context Parallelism

Yifan Niu, Han Xiao, Dongyi Liu +2

Scaling long-context capabilities is crucial for Large Language Models (LLMs). However, real-world data contain a large number of sequences with heterogeneous lengths. Existing tra…

cs.AI2026

PiCA: Pivot-Based Credit Assignment for Search Agentic Reinforcement Learning

Dongyi Liu, Yifan Niu, Qinwen Wang +2

Large Language Model (LLM)-based search agents trained with reinforcement learning (RL) have significantly improved the performance of knowledge-intensive tasks. However, existing…

cs.LG2026

IBCircuit: Towards Holistic Circuit Discovery with Information Bottleneck

Tian Bian, Yifan Niu, Chaohao Yuan +7

Circuit discovery has recently attracted attention as a potential research direction to explain the non-trivial behaviors of language models. It aims to find the computational subg…

cs.LG2026

Mitigating the Safety Alignment Tax with Null-Space Constrained Policy Optimization

Yifan Niu, Han Xiao, Dongyi Liu +2

As Large Language Models (LLMs) are increasingly deployed in real-world applications, it is important to ensure their behaviors align with human values, societal norms, and ethical…